1. Field of the Invention
This invention relates to free-flowing, pumpable water-containing alkyl sulfate pastes, to a process for the production of alkyl sulfate pastes having improved flow properties by addition of alkenyl sulfates and to the use of such pastes for the production of detergents and cleaning preparations.
2. Statement of Related Art
Anionic surfactants of the alkyl sulfate type, more especially those containing C.sub.16-18 alkyl radicals, show excellent detergent properties and are used both in liquid and in powder-form detergents and cleaning preparations.
The detergents in question are generally produced from water-containing alkyl sulfate pastes. To avoid unnecessary mass transport, it is an advantage if water-containing surfactant pastes have a high solids content. However, alkyl sulfate pastes can only be concentrated to a certain solids content. In addition, pastes such as these show non-newtonian flow behavior. Above a limit of around 55% by weight solids, the viscosity generally reaches such high values that the pumpability of the surfactant solutions is no longer guaranteed, even at elevated temperatures. Thus, water-containing fatty alcohol sulfate pastes with solids contents of 30 to 70% by weight have such high viscosities and yield points, even at ambient temperature, that they often cannot be transferred from one vessel to another or pump-circulated.
According to EP 024 711, polyalkyl ether glycol sulfates are added to high-viscosity surfactant concentrates to reduce their viscosity. Whereas compounds such as these are eminently suitable for reducing the viscosity of alkyl ether sulfate, alkylaryl ether sulfate, alkyl benzenesulfonate and alkylaryl sulfosuccinate solutions, their performance in the presence of alkyl sulfates, particularly linear primary alkyl sulfates, is often unsatisfactory.
DE-OS 34 47 859 describes the use of alkanesulfonates as viscosity regulators for high-viscosity anionic surfactant concentrates, more especially salts of .alpha.-sulfofatty acid esters.
DE-OS 37 18 896 describes the use of alkoxylated alcohols as viscosity regulators for high-viscosity alkyl benzenesulfonate concentrates.